Preventive Health Behaviors among Vegetable Farmers in Indonesia: An Application of the Extended Theory of Planned Behavior

Background: Farmers in low- and middle-income countries face serious occupational and environmental health risks, including pesticide exposure, musculoskeletal disorders, and skin diseases. In Indonesia, limited evidence exists on the psychosocial factors that shape preventive health behaviors, hindering the design of effective interventions. This study applies an extended Theory of Planned Behavior (TPB) framework to analyze preventive practices among vegetable farmers. Methods: A cross-sectional survey was conducted among 254 vegetable farmers in Koto Laweh Village, West Sumatra, Indonesia, during July–August 2025. Data were collected using a validated TPB-based questionnaire and analyzed with Partial Least Squares Structural Equation Modelling (PLS-SEM). Results: Knowledge had a strong positive effect on attitudes, while both attitudes and perceived behavioral control (PBC) significantly predicted intention. Subjective norms were not significant. Intention emerged as the dominant predictor of behavior, with PBC exerting a smaller but direct influence. The extended model accounted for substantial variance across constructs (R² = 0.53 for attitude, 0.60 for intention, and 0.83 for behavior). Conclusion: Preventive behavior among Indonesian farmers is mainly driven by the knowledge–attitude–intention pathway, reinforced by perceived behavioral control. Intention is the strongest predictor, while family norms are weak and institutional norms are more relevant. Interventions should strengthen education, skills, and institutional support to foster sustainable occupational health practices. Keywords: Theory of Planned Behavior, Environmental and occupational health, Preventive behavior, Farmers, SEM-PLS.